This invention relates to a furnace assembly for burning combustible wastes, especially city- and factory wastes.
In almost all conventional furnaces of the above kind, the exhaust hot gases discharged from the exhaust discharge passage, such as funnel, chimney shaft, flue or the like, and yet preserving a large amount of thermal calories, are dissipated in the atmospheric air, so to speak, without recovering the preserved calories.
It is therefore a much desired aim among those skilled in the art to realize an improved burning furnace capable of recovering substantial part of such waste heat and providing an energy-sparing characteristic. Such advantage is highly valuable in consideration of nowaday's high energy cost.
Another national grave problem is the atmospheric pollution which is mainly caused by the discharge of considerable amount of smoke and soot. Various proposals for solving this kind of pollution problem have been proposed and brought into practical use, however, only with partial satisfaction. In fact, these prior proposals have met with other difficulties. In the case of the centrifuge, the collecting effect is relatively small, with respect of soot, on account of very small specific gravity thereof.
In the case of the electric dust collector of the static type, on the other hand, electrical charge will be accumulated in the once collected soot particles which are inclined to have soon the same electrical polarity with the collecting electrode and repulsed and reattracted repeatedly and finally carried away into the atmospheric air, by being accompanied by the discharging exhaust gas streams. When it is intended to reburn the soot, the furnace must have large outline dimensions. Even with such measures, the reburning effect is still smaller than expected. Therefore, these conventional measures are unsuccessful to treat the soot and the like unburnt particles for well preventing atmospheric air pollution.
It is frequently desired in the use of the burning furnace to treat waste brake linings which comprise asbestos fibers molded with a synthetic resin material, or waste grinding wheel blocks which comprise abrasive particles molded again with synthetic resin together, for recovering these valuable fibrous or granular materials, after the removal burning of the contained molding resin. However, it has been experienced that with the conventional burning furnace, a considerable amount of unburnt resin in the form of soot particles is liable to remain as impurities which prevent the desired direct reutilization of the effective recovered material.